a. Field of the Invention
This invention relates to a similar shape part program creation method and, more particularly, to a part program creation method suited to creation of a part program for machining a part having a plurality of similar shapes.
b. Description of the Related Art
In an automatic programming system for creating NC data using an automatic programming language such as APT (automatically programmed tools) or FAPT,
(a) a part program based on the automatic programming language is created by defining points, straight lines and circular arcs using simple symbols (this is referred to as "figure definition"), and defining a profile using the defined points, straight lines and circular arcs (referred to as "part profile definition"). Then, defining a tool path by an approach motion statement which causes the tool to approach, a profile motion statement which moves the tool along the part profile, and a withdrawal motion statement which causes the tool to withdraw (referred to as "motion statement definition"), and
(b) the part program based on the automatic programming language is subsequently converted into NC data comprising NC data (EIA codes or ISO codes) in a format capable of being executed by an NC unit.
When a part program is created for machining a part having a plurality of similar shapes (inclusive of identical shapes), the conventional part program creation method is such that motion statement definition for such operations as approach/profile motion/withdrawal must be repeated even though the machining method is the same. The problem that results is that a great amount of time is required to create the part program.